What can Jeff Mathis and Mike Napoli tell us about the dangers of valuing backup catchers inappropriately?

Believe it or not, most of our writers didn't enter the world sporting an @baseballprospectus.com address; with a few exceptions, they started out somewhere else. In an effort to up your reading pleasure while tipping our caps to some of the most illuminating work being done elsewhere on the internet, we'll be yielding the stage once a week to the best and brightest baseball writers, researchers and thinkers from outside of the BP umbrella. If you'd like to nominate a guest contributor (including yourself), please drop us a line.

Jonathan Bernhardt is a freelance writer born in Baltimore who lives and works in New York City. He is an occasional contributor to the Et tu, Mr. Destructo? blog.

If you didn’t catch tonight’s NLDS finale between the Milwaukee Brewers and the Arizona Diamondbacks, you missed quite the game. Framed as a potential pitchers’ duel between Ian Kennedy and Yovanni Gallardo, the two starters didn’t disappoint. Each went six innings, pitching well enough to maintain the pitchers’ duel pretense but allowing enough action to keep the fans excited—a perfect blend. The announcers commented during the game that every base hit is a rally in the playoffs, and while that might be a bit of an exaggeration, it definitely felt like it in a back-and-forth game like this.

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As Rob McQuown did, I’m taking my dollar values from lastplayerpicked.com, and we’ll all be adding the extra “Super Deep” category (20 teams with 10 keepers) for BP readers in the deepest of leagues. Think of it as an even deeper Keeper Reaper. If you missed it earlier this week, read the beginning of Rob's column for an introduction to what Keeper Reaper is all about. Remember, here are how league depths are determined:

How the Diamondbacks have managed to exceed expectations and set themselves up for a playoff run.

When I last checked in on the NL West race two weeks ago, the Giants had fallen three-and-a-half games behind the Diamondbacks, though they still held a 62.8 percent chance of reaching the playoffs according to BP’s odds. As if on cue, the Snakes immediately fell into a six-game losing streak that trimmed the division lead to a single game, but they soon turned around and peeled off a nine-game winning streak, rebuilding their lead to six games. Going into a three-game weekend series against the Giants, Playoff Odds report now puts Arizona's chances of winning the division at 82.9 percent with the defending world champions knocked down to 17 percent. In a year with vanishingly few races, this too is on the verge of fading from sight.

In his fifth Asian Equation column, Michael looks at the relievers who have enjoyed modest success--and failure--making the move from Japan to America.

The last group in my analysis of the player’s who have migrated to MLB from Nippon Professional Baseball (NPB) are the relievers, the least appreciated members of a successful baseball team. Yet, of all NPB imports, they have been the most numerous (explaining the length of this article, for which I apologize in advance) and the cheapest. Diminished quality is the most obvious reason for these extremes, since starters who don’t meet MLB standards get shifted to the bullpen, and lesser talents also keep salaries down. Additionally, the typical NPB pitcher’s arsenal matches well with an MLB reliever’s skillset.

As I discussed in my last Asian Equation article, NPB is a breaking ball league, which translates better to relief than starting. A good breaking ball might fool major league hitters the first or second time they see it in a game, but it probably won’t the third or fourth time. As an illustration, here’s how batter OPS rises against two of the biggest NPB starting-pitcher busts as compared with three current MLB pitchers: the best, the most mediocre, and an old junkballer. While MLB batters’ performance improves against each pitcher the more times they see him in a game, the change is far more dramatic with Matsuzaka and Kawakami.

Jay looks at the Dodgers' deadline deals and wonders what they were thinking when they traded Travyon Robinson.

It's fair to say the Dodgers aren't accustomed to selling at the July 31 non-waiver trading deadline. The last time they were lousy enough to go into the deadline far enough removed from a playoff spot to be sellers was 19 years ago when they were en route to 99 losses: their worst season in 83 years. Not that they hadn't failed to recognize the need to do so last summer when they were seven games back in the NL West and 5 1/2 games back in the Wild Card; a more honest assessment of their chances would have had general manager Ned Colletti selling off parts in exchange for prospects. This week, the Dodgers finally got a chance to see Colletti doing just that, and the sum of his moves and non-moves was enough to make a fan pine for the days of Octavio Dotel.

Kevin looks at what each contender is looking for and the prospects they could deal to meet their needs.

I'm going to be straight with you. I am not a big fan of the trade speculation game. Don't get me wrong, I like the rumors and hearing inside scoop of what really is (or isn't) going on between teams, but the sitting around the fire (or bar, or TV) game of “What would Team X have to give up for Player Y?” just doesn't appeal to me. We can all figure out what would make both sides of the ledger even out on a talent level, but what we don't know is how big of a role the one player that shows up in nearly every deal, Mr. Cash Considerations, will play. As we've already seen with the K-Rod to Milwaukee deal, sometimes money (or relief from money) is all that matters in a deal. So let's think about real teams, real contenders, and what kind of prospects they might be dangling out there in an attempt to get that extra piece (or maybe even one of the big prizes) while reviewing what they are looking for based on recent discussions with several team executives.